Prior practice has been to combine a plurality of photovoltaic solar cells into a flat rectangular module of selected size, and then form a flat array consisting of a plurality of such modules. By way of example, one suggested prior art technique involves assembling a plurality of solar cells so as to form rectangular modules measuring approximately 1'.times.4', with each module being surrounded and supported at its edges by a rigid frame made of a suitable material, e.g., aluminum. These modules are intended to be mounted in a rigid grid-like (i.e., trellis-like) framework forming part of a pivotal support structure, with the grid-like framework having a plurality of openings each sized and adapted to accommodate a single module in a nesting relationship. The several modules are electrically connected in parallel or in series, according to the power output requirements of the operator. Another arrangement consists of mechanically and electrically connecting two or more modules as an integrated structure, which structure is frequently referred to as a "solar panel". These panels in turn are mounted on a pivotal support structure.
According to efficient practice, the pivotal support structure is oriented so as to cause the modules or panels to face the sun. To maximize the concentration of incident solar energy, efforts have been made to provide a suitable support structure adapted to adjust the orientation of the panels to accommodate for variations in the angle of the sun during various seasons of the year and during each day of a given season, i.e., solar tracking means.
Photovoltaic solar modules and panels mounted in ground or roof installations catch and are stressed by the wind. The buffeting effect by winds of even modest velocity, e.g., 10 miles per hour, places the panels and their supporting structure under relatively high stress. As an economy measure, particularly where two or more panels are mounted in tandem on the same support structure, it is common to orient the pivotable support structure so that the panels extend north to south and to limit the panel-adjusting means to a single axis mode of operation whereby the panels can be pivoted east to west on a north/south pivot axis to compensate for variations in the angle of the sun from sunrise to sunset.
Nevertheless, in the interest of withstanding high winds, the common practice has been to utilize relatively massive support structures, some with cross-braces that serve to provide panels with added deformation resistance as well as to connect them to the support structure. These relatively massive support structures are costly and cumbersome and constitute another factor tending to discourage widespread use of arrays of photovoltaic panels as economical sources of electrical power. Furthermore, they are especially objectionable from a cost standpoint when utilizing a plurality of relatively large silicon solar cell modules, e.g., modules that measure 4'.times.6'.
The primary object of this invention is to provide a photovoltaic solar energy collection and conversion system that is characterized by a simple, relatively inexpensive solar module support structure.
Another object is to provide a new and improved mechanical structure for pivotally mounting a plurality of photovoltaic modules and panels in a planar array that is unified so that a single mechanism may be used to simultaneously and correspondingly change the angle of declination of the array.
A more specific object is to provide a solar energy electrical power source comprising at least two flat photovoltaic panels disposed in co-planar side-by-side relation and an improved support structure for supporting the panels for pivotal movement on a pivot axis that extends transversely of the panels, the improved structure including selectively operable means for pivoting all of the panels simultaneously and by the same amount of angular displacement.
A further specific object is to provide a support mechanism for supporting and tracking multiple photovoltaic modules wherein individual structural members perform multiple tasks.
These and other objects and advantages of the invention are achieved by providing (1) at least two flat PV panels in side by side and co-planar relation, (2) a pivot shaft extending transversely of the side-by-side panels, (3) at least two supports spaced apart lengthwise of the shaft, (4) means for mounting the pivot shaft to the at least two supports, (5) means for connecting the panels to the pivot shaft so that the panels can pivot about the longitudinal axis of the shaft, (6) means for mechanically coupling all of the panels together so as to form a unified flat array, and (7) electro-mechanical drive means for (a) mechanically pivoting the unified array about the aforesaid axis and (b) locking the array against pivotal movement when the electro-mechanical drive means is deenergized.
Other objects, features and advantages are set forth in the following detailed description of a preferred embodiment of the invention which is to be considered together with the accompanying drawings.